1 files changed, 41 insertions, 30 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 2c5ffd664..61f693e1b 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -1,9 +1,10 @@
 use std::cell::RefCell;
 use std::fmt::Debug;
 
+use super::FulfillmentContext;
 use super::TraitEngine;
-use super::{ChalkFulfillmentContext, FulfillmentContext};
 use crate::solve::FulfillmentCtxt as NextFulfillmentCtxt;
+use crate::traits::error_reporting::TypeErrCtxtExt;
 use crate::traits::NormalizeExt;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::ErrorGuaranteed;
@@ -24,27 +25,25 @@ use rustc_middle::ty::ToPredicate;
 use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::config::TraitSolver;
-use rustc_span::Span;
 
 pub trait TraitEngineExt<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>) -> Box<Self>;
-    fn new_in_snapshot(tcx: TyCtxt<'tcx>) -> Box<Self>;
+    fn new(infcx: &InferCtxt<'tcx>) -> Box<Self>;
 }
 
 impl<'tcx> TraitEngineExt<'tcx> for dyn TraitEngine<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>) -> Box<Self> {
-        match tcx.sess.opts.unstable_opts.trait_solver {
-            TraitSolver::Classic => Box::new(FulfillmentContext::new()),
-            TraitSolver::Chalk => Box::new(ChalkFulfillmentContext::new()),
-            TraitSolver::Next => Box::new(NextFulfillmentCtxt::new()),
-        }
-    }
-
-    fn new_in_snapshot(tcx: TyCtxt<'tcx>) -> Box<Self> {
-        match tcx.sess.opts.unstable_opts.trait_solver {
-            TraitSolver::Classic => Box::new(FulfillmentContext::new_in_snapshot()),
-            TraitSolver::Chalk => Box::new(ChalkFulfillmentContext::new_in_snapshot()),
-            TraitSolver::Next => Box::new(NextFulfillmentCtxt::new()),
+    fn new(infcx: &InferCtxt<'tcx>) -> Box<Self> {
+        match (infcx.tcx.sess.opts.unstable_opts.trait_solver, infcx.next_trait_solver()) {
+            (TraitSolver::Classic, false) | (TraitSolver::NextCoherence, false) => {
+                Box::new(FulfillmentContext::new(infcx))
+            }
+            (TraitSolver::Next | TraitSolver::NextCoherence, true) => {
+                Box::new(NextFulfillmentCtxt::new(infcx))
+            }
+            _ => bug!(
+                "incompatible combination of -Ztrait-solver flag ({:?}) and InferCtxt::next_trait_solver ({:?})",
+                infcx.tcx.sess.opts.unstable_opts.trait_solver,
+                infcx.next_trait_solver()
+            ),
         }
     }
 }
@@ -58,11 +57,7 @@ pub struct ObligationCtxt<'a, 'tcx> {
 
 impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
     pub fn new(infcx: &'a InferCtxt<'tcx>) -> Self {
-        Self { infcx, engine: RefCell::new(<dyn TraitEngine<'_>>::new(infcx.tcx)) }
-    }
-
-    pub fn new_in_snapshot(infcx: &'a InferCtxt<'tcx>) -> Self {
-        Self { infcx, engine: RefCell::new(<dyn TraitEngine<'_>>::new_in_snapshot(infcx.tcx)) }
+        Self { infcx, engine: RefCell::new(<dyn TraitEngine<'_>>::new(infcx)) }
     }
 
     pub fn register_obligation(&self, obligation: PredicateObligation<'tcx>) {
@@ -202,17 +197,24 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         }
     }
 
+    pub fn assumed_wf_types_and_report_errors(
+        &self,
+        param_env: ty::ParamEnv<'tcx>,
+        def_id: LocalDefId,
+    ) -> Result<FxIndexSet<Ty<'tcx>>, ErrorGuaranteed> {
+        self.assumed_wf_types(param_env, def_id)
+            .map_err(|errors| self.infcx.err_ctxt().report_fulfillment_errors(&errors))
+    }
+
     pub fn assumed_wf_types(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        span: Span,
         def_id: LocalDefId,
-    ) -> FxIndexSet<Ty<'tcx>> {
+    ) -> Result<FxIndexSet<Ty<'tcx>>, Vec<FulfillmentError<'tcx>>> {
         let tcx = self.infcx.tcx;
-        let assumed_wf_types = tcx.assumed_wf_types(def_id);
         let mut implied_bounds = FxIndexSet::default();
-        let cause = ObligationCause::misc(span, def_id);
-        for ty in assumed_wf_types {
+        let mut errors = Vec::new();
+        for &(ty, span) in tcx.assumed_wf_types(def_id) {
             // FIXME(@lcnr): rustc currently does not check wf for types
             // pre-normalization, meaning that implied bounds are sometimes
             // incorrect. See #100910 for more details.
@@ -225,10 +227,19 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
             // sound and then uncomment this line again.
 
             // implied_bounds.insert(ty);
-            let normalized = self.normalize(&cause, param_env, ty);
-            implied_bounds.insert(normalized);
+            let cause = ObligationCause::misc(span, def_id);
+            match self
+                .infcx
+                .at(&cause, param_env)
+                .deeply_normalize(ty, &mut **self.engine.borrow_mut())
+            {
+                // Insert well-formed types, ignoring duplicates.
+                Ok(normalized) => drop(implied_bounds.insert(normalized)),
+                Err(normalization_errors) => errors.extend(normalization_errors),
+            };
         }
-        implied_bounds
+
+        if errors.is_empty() { Ok(implied_bounds) } else { Err(errors) }
     }
 
     pub fn make_canonicalized_query_response<T>(